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Since met winter is coming to a close it's time for the Spring 2016 Tennessee Valley Edition.I changed the wording on the Nina thread to just Nina and took out  the spring discussion.This way there is no confusion with two different topics.

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Day 2 Outlook from the SPC:

day2otlk_0700.gif?1456726362775

...LOWER MS/TN/OH VALLEYS INTO APPALACHIANS...

IT STILL APPEARS THAT LOW-LEVEL MOISTURE RETURN TO THE WARM SECTOR

OF THE DEVELOPING LOW WILL REMAIN AT LEAST SOMEWHAT MARGINAL FOR

SEVERE WEATHER POTENTIAL INLAND OF WESTERN AND CENTRAL GULF COASTAL

AREAS. HOWEVER...A PLUME OF INITIALLY STEEP MID-LEVEL LAPSE RATES

MAY CONTRIBUTE TO AT LEAST WEAK BOUNDARY LAYER CAPE DURING THE

DAY...IN THE PRESENCE OF STRENGTHENING DEEP LAYER MEAN WIND FIELDS.

THIS MAY INCLUDE SOUTH SOUTHWESTERLY 850 MB FLOW STRENGTHENING TO

50-60+ KT ACROSS TENNESSEE/KENTUCKY AND PORTIONS OF ADJACENT STATES

BY TUESDAY AFTERNOON...WHILE A 90+ KT CYCLONIC...WESTERLY 500 MB JET

NOSES ACROSS THE OZARK PLATEAU THROUGH THE TENNESSEE VALLEY.

POTENTIAL CONVECTIVE EVOLUTION REMAINS UNCERTAIN AT THIS POINT.

HOWEVER...STRONG FORCING FOR ASCENT MAY SUPPORT ONE OR MORE

ORGANIZED LINES OR CLUSTERS OF STORMS ACROSS THE OHIO/TENNESSEE

VALLEYS...PERHAPS SOUTHWARD TOWARD THE LOWER MISSISSIPPI VALLEY.

DAMAGING WIND GUSTS AND PERHAPS A FEW TORNADOES WILL BE POSSIBLE AS

ACTIVITY RAPIDLY SPREADS TOWARD THE CENTRAL AND SOUTHERN

APPALACHIANS THROUGH LATE TUESDAY EVENING...BEFORE DIMINISHING.

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JIT Just In Time severe weather set-up is possible on Tuesday. SPC Slight is the way to go with so much up in the air. JIT moisture is a typical issue this time of year. JIT wind fields are also forecast this time. The system starts as positively tilted slop coming out of the Midwest. Late afternoon a more vigorous vort max comes out of Missouri. Show Me State going to show us some action?

 

Pos tilt slop turns neutral late Tuesday afternoon to slightly negative overnight, but all JIT. If the vort max fails, the wind fields fail, and the moisture certainly fails. SPC notes the conditional set-up. Missouri has to Show Me the vort max!

 

Now if things come together right, I could see SPC going Enhanced for Tuesday. I see no path to MDT though. ENH scenario would include the warm front sharpening up as the MO vort max drives into the Valley. Nice WF intersection with CF is forecast in Middle Tenn. I would not chase that intersection though, with cold right on the CF. Look for a gravity wave or other (outflow) boundary ahead of CF intersecting with the WF. No solid pre-frontal trough is forecast, and I would not expect one tomorrow, so it will be a work in progress. 

 

Severe Tuesday is conditional. I expect a few strong wind reports. Tornadoes depends on everything coming together JIT. The good news is that it's back yard material BNA, CHA, HSV depending on boundary intersections. With no travel necessary, one can relax and decide in the morning.

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JIT Just In Time severe weather set-up is possible on Tuesday. SPC Slight is the way to go with so much up in the air. JIT moisture is a typical issue this time of year. JIT wind fields are also forecast this time. The system starts as positively tilted slop coming out of the Midwest. Late afternoon a more vigorous vort max comes out of Missouri. Show Me State going to show us some action?

Pos tilt slop turns neutral late afternoon to slightly negative overnight, but all JIT. If the vort max fails, the wind fields fail, and the moisture certainly fails. SPC notes the conditional set-up. Missouri has to Show Me the vort max!

Now if things come together right, I could see SPC going Enhanced. I see no path to MDT though. ENH scenario would include the warm front sharpening up as the MO vort max drives into the Valley. Nice WF intersection with CF is forecast in Middle Tenn. I would not chase that intersection though, with cold right on the CF. Look for a gravity wave or other (outflow) boundary ahead of CF intersecting with the WF. No solid pre-frontal trough is forecast, and I would not expect one tomorrow, so it will be a work in progress.

Severe Tuesday is conditional. I expect a few strong wind reports. Tornadoes depends on everything coming together JIT. The good news it hat it is back yard material BNA, CHA, HSV depending on boundary intersections. With no travel necessary, one can relax and decide in the morning.

I know the SPC included all of East Tennessee in the slight risk, but what are your thoughts as far as the eastern extent of this system? To me, a line coming off the plateau gives me a red flag of "Plateau could weaken the storms before they reach the valley".

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Someone on Facebook asked MRX if there was a chance for supercells tomorrow evening. Here's their response:

Embedded supercells in the line are possible, but as far as individual supercells, the chances of that are very low.

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Interesting. The SPC has put portions of the Central Valley back into the Slight risk area. Pretty much from Knox County and points west are in the Slight risk, while areas East of Knox County is in the Marginal risk.

day1otlk_1200.gif?1456813111502

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The 12z NAM...welp, that is a bit different for Thursday night. The mountains at the very least may get some huge snow amounts. NE TN still in this surprisingly, especially southwest VA.

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12z CMC for TR night has a decent track for big mtn snows and still holds potential for the northern Valley and Plateau. The system continues to jog south towards the Euro solution from the past few days.

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Rumored Super Tuesday severe was last week during early voting. Today is a debacle, and a waste of a good outflow boundary in North Alabama. Let us severe enthusiasts take one for the public. They don't need that action in Alabama.

 

Go by the Euro for mountain snow Thursday night. GFS progressive bias rushing things too quickly Thursday night. Prefer the Euro showing more digging. Valley will miss out but the mountains are looking good Thursday evening into Friday morning. Friends near Blue Ridge might see more CAD benefit, but the Tennessee mountains will be cold enough by elevation.

 

That may be it for winter. MJO phase 8 ends, basically wasted like that Bama outflow on the severe side. Pattern goes super warm next week into the following week. Any AO flirtations look weak, short-lived, or Europe side mid-March. Thankfully between snow and true severe season we have NCAA March Madness!

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Wow Bessemer AL in the suburbs of Birmingham, and Opelika near Auburn, had tornadoes yesterday. I thought the outflow would not do much yesterday, but the JIT set-up verified there. Temps and Dews were marginal right up to the event. What is this the new High Plains? I think the vigorous short-wave with a small wavelength was able to gather the ingredients locally last minute, because it had an outflow boundary to work with down there.

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The 12z NAM shows 2-4 inches over my house and nothing for KTRI. Interesting solution.

Are you speaking of tomorrow night? Interesting to see the NAM, RGEM, and 6z GFS taking the coastal closer to the big cities...the mtns may get plastered. Still wouldn't rule out some mischief in your area....MRX had a good disco this AM. If that coastal keeps getting deeper, that precip shield will be stronger.

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Are you speaking of tomorrow night? Interesting to see the NAM, RGEM, and 6z GFS taking the coastal closer to the big cities...the mtns may get plastered. Still wouldn't rule out some mischief in your area....MRX had a good disco this AM. If that coastal keeps getting deeper, that precip shield will be stronger.

I was yeah but it was a very marginal solution. I haven't looked at any runs this morning.

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Just for verification purposes...February finished above normal at Chatt, TYS(barely), TRI, and Oak Ridge.  The warm phases of the MJO had signaled warmth that would erase the negative temp departures from the second week of February.  Indeed, those below normal temps were completely erased.   IMO, the complete evacuation of cold air from the lower 48 and southern Canada made it next to impossible for phase 8 of the MJO to have much of an impact.  The Super Nino flooded the lower 48 w/ Pacific air and was very slow to let go once established.  It has been a very good indicator during the past few winters(not perfect by any means).  But it does show how much the tropics influence our area....

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I was yeah but it was a very marginal solution. I haven't looked at any runs this morning.

 

The coastal low has deepened on most meso models and backed a bit west.  Nothing really to impact our sensible weather yet.  But I generally pay attention to wx systems in early March that are to our south and arrive at night.   I cast just a lazy eye towards that system if only because it is probably our last chance at seeing snowflakes for a while.  But it is interesting to see the coastal back towards the coast versus the OTS solution that went south of Hatteras for several runs.   Will be interesting to see how far west it goes, even at this late time frame for the models. 

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Wow Bessemer AL in the suburbs of Birmingham, and Opelika near Auburn, had tornadoes yesterday. I thought the outflow would not do much yesterday, but the JIT set-up verified there. Temps and Dews were marginal right up to the event. What is this the new High Plains? I think the vigorous short-wave with a small wavelength was able to gather the ingredients locally last minute, because it had an outflow boundary to work with down there.

Grew up near Midfield close to Bessemer when i was young.When i was young mom took me and my older brother to the Southern league All-Star's baseball game at Rickwood Field.About the 6th inng it started to thunder,back then they kept playing.Then shortly after it started to hail and rain and everyone ran for cover,then the power shut down and the game was called,on the way home we found out a tornado hit about a half mile from the ball park.

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I hope you are just making fun of that analog...

That won't happen.That must have been some real cold air watching the man shovel the snow with no problem.They must have had some unreal snow ratios to get that amount.

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